Radiochemistry: inconvenient but indispensable

Radiochemistry has always been and still is a crucial tool in the field of radionuclide determination, both for high and low level works; this holds p articularly in the case of alpha and beta emitters. Requests to the analyst are increasingly demanding in terms of performance (detection limit, relia bility, accuracy, precision,...), but also of economy (cost, time,...) and of flexibility with respect to sample types. In general, chemical and radio chemical analyses consist of four main steps: sample pre-treatment includin g pre-concentration, dissolution and/or digestion, separation of analytes f rom the matrix and from each other, transformation of the separated fractio n into a source suited for measurement, determination of the amount or the activity of the analytes. The required combination of sub-procedures is det ermined by the analytes under investigation, their absolute and relative am ounts, the matrix composition and by the performance required. IRMM's Analy tical Chemistry Unit started several years ago to develop, adapt and/or val idate various radiochemical methods and procedures, and apply these to diff erent measurement tasks. This paper gives an overview on recent and ongoing activities. (C) 2000 Elsevier Science Ltd. All rights reserved.